cardwell



Feb. 12, 1929. 1,702,037

J. R. CARDWELL DRAFT GEAR Filed Dec. 14; 1923 2 Sheets-Sheet 1 fnafenar: may 1?. Cardwell Febliz, 1929.

J. R. CARDWELL DRAFT GEAR Filed Dec. 14, 1925 2 Sheets-Sheet 2 Patented Feb. 12, 1 929.

* UNITED STATES PATENT OFFICE.

JAMES R. CARDWELL, OF CHICAGO, ILLINOIS, ASSIGNORTO UNION DRAFT GEAR COM- IPA'NY, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

DRAFT GEAR.

Application filed December 14, 1923. Serial No. 680,589.

The invention relates to draft gears for railway cars, of the friction type, its ob ects being to secure a high degree of efliciency,

certainty and being shown in detail;

7 two draft sills 10 and cooperates with a pair Fig. 2 is a sectional view of the gear on the line 22 of Fig. 1;-

Fig. 3 is a view similar to Fig.1, the gear being under compression, some ofthe parts being shown in plan and some broken away; Fig. 4 is a view in perspective of one of the friction shoes ofthe gear;

Fig. 5 is an end elevation of a combined friction spring seat and actuating bar; and Fig. 6 is a view in perspective of one of the friction plates.

The gear is adapted for use in connection with the standard form of railwa car and coupler, and in service is mounte between of draft lugs11,'12 and a'pair'ofbutfing lugs 13, 14, attached to the sills, and is actuated by a coupler 15 having any desired form of loop or extension as indicated at16.

The improved. gear comprises a pair of chambered followers 17, 18, which engage respectively the draft and buffing lugs. Within these followers is mounted two groups of intercalating friction plates 19, 20. vThe friction plates, one of which is {shown in perspective in Fig. 6 and designated by the numeral; 21, are alike in shape,

having, generally speaking, an oblong, rectangular form. Each is provided near one end with lateral recesses 22, 23, formlng shoulders-for engagement by an actuating bar,and at the opposite end having its side margins cut away as indicated at 24, 25, to provide clearance for the actuating bar associatedwith the companion set of plates.

Each group of plates is made up of two sets reversely arranged, one set as 26 having its recessed ends located adjacent the end wall of the follower 17 and the other set 27 located adjacent the end wall of the follower '18. The length of the plates is slightly less than the distance between the end walls of the two, followers when the gear is fully compressed.

'Housed within each of the followers is a pair of friction shoes 28, 29 and 30, 31, the members of each pair being on opposite sides of the axis of the gear and slidably engaging the inner plate of the adjacent group. These friction shoes are alike in form, one of them being shown in perspective in Fig, 4. Each is provided on its inner face with a vertical pivot rib 32; A pair of toggle elements 33, 34, and 35, 36 is interposed between the members of each pair of friction shoes and recessed to engage and turn upon the ribs 32. The adjacent faces of each pair of toggle members are curved and lie in contact. At the inner end of the curved face of each there is.

responding sets of friction plates of each group and engaging in the recesses at the tops and bottoms thereof, the inner shoulders of the several plates being normally in engagement with the end portions of the bars 37, 38 as indicated in Fig. 1.

In advance of the pivot ribs 32 each of the friction shoes as 28 is provided with a forwardly facing shoulder 44. An annular spring seat 45, 46 cooperates with the shouldersof each pair of friction shoes and between these seats there reacts a releasing spring 47. I r

The cross members of both followers are centrally apertured as shown at 48, 49 for the admission of a bolt, not shown, for holding the elements of the gear in assembled relation preliminary to installation, which bolt may, if desired, be removed when the ance of the' spring l7.

s V 41 both pairs of toggle' eleinents are caused gear.

described occupy; the. positions as, shown in:

Fig. 1, theside walls of the two followers being spaced apart a distance equal tothe maxnnum compressive 1 movement. of the Upon advance movement of either follower the friction shoes associated with it are carriedforwardly against the resist- The toggle elements associatedwith-these shoes are urged forwardlyagainst the abutment bar 87 or 38 and by reasontof the resistance of the spring to turn on their.,pivots,'their contacting faces rolling, each upon the other, thefric tion shoes bein thus ur ed outwardl and l r I v p e c J I pressing: the friction plates together.

Aisthefollower continues to advance thefriction plates directlyassociated therewith are carried: forward, sliding between the plate's'ofthe cooperatingset. The actuating bars as 42 associated with theplates which care urged forward are carried with them,

the abutment bars as -87,l1owever, moving out (if/contact ,with the actuating bars as the travel of, the latter does not ronnnence 7 until the ends of the fri-c ion plates as which are normally spacedfa short distance from the adjacent eiichwall of the followr V1. are engaged thereby. r s

Tli'e' compressive actionv upon thefricuon plates due to the relative movement of cooperating toggle'ineinbers gradually increases during the compression offthe' gear, due

tothe cumulative resistance of the s ring 41/ U' on the-relieflof the stresses which have caused the compression of the gear, release 1s, effected by the spring 47, which, being more powerful than the spring 41, forces baclrthe; friction shoeswith greaterforce than is applied to-the, toggle elements by the latter spring. Tllhe compressive action upon-the cpl-ates, isthus relieved and the latter, are restored to normal positi'onby the bars" as 42, which alecarried backwardly by the bars as 37."

The shocks of service are absorbed by the springs and the friction developed betweenlthe plates themselves and between the outer and inner plates, respectively, and the side walls of the followers and the friction-shoes, The resistance to compression of the gear being gradually developed, the action is smooth and as the spring 41 tends at all times to spread the toggle elements the release is correspondingly smooth,

though rendered certain by the p'repo'n-;

,deratingpower of, the spring li".

' VVhilea highly'efficient, and so far as: now advlsed, preferred form of construction is illustrated, various changes in the form and arrangement of the parts may be made within its scope.

I claim as my invention:

1; In a draft gear, in combination, a pair of chambered.followers, twogroups of intercalating friction plates housed within the followers, a pair of friction shoes housed withiireach follower and in engagement with the end wall thereof, the shoes of each pair bearing outwardly against the friction plates, a pair of toggle elements cooperating with each pair of shoes, a spring reacting between the two sets of toggle elements, a spring reacting between the two pairs of shoes, and means. for retracting the advanced plates upon release.

2.' Ina draft gear, in combination, a pair of chambered followers, two groups of intercalating friction plates housed within. the followers, a pair of friction shoes housed within each follower and in engagen'icnt with the end wall thereof, the shoes of each pair bearing outwardly against the friction plates, a pair oftoggle elements cooperating with each pair of shoes, a spring reacting between the two sets of toggle elements, a spring of greater power reacting between the two pairs of shoes, and means for retracting the advanced plates upon release.

In a draft gear, in combination, a pair of chambered followers, two groups of intercalating friction plates housed within. the followers, a pair of friction shoes housed within each follower and bearing laterally against the friction plates, each shoe being formed with a pivot rib, and a forwardly facing shoulder, a pair of toggle elements withi 1 each follower, each of such elements pivotally engaging one of the pivot ribs, a spring reacting between the two sets of toggle elements, a spring reacting between the shoulders of shoes at oppositecnds of the gear and means for retracting the ad vanced' plates upon release.

at. In a draft gear, in combination, a pair of cliambered followers, two groupsof intercalating friction plates housed withinthc followers, a pair of friction shoes housed within each follower and in engagement with the endwall there of',,tl 1e shoes of each pair bearing outwardly against the friction plates, a pair oftoggle elements cooperating with eachpair of shoes,a spring reacting between the twosets of toggle: elements and a spring reacting between the two pairs of shoes, a retracting bar within eachfollowcr engaging shoulders on one set of friction plates of each group and being acted upon by the first named spring.

5. A draft gear including a pair of fol lowers,n1eans whereby one of saidfollowers is moved toward the other when the gear is subjected to compressive strains, two sets of intercalated friction plates, means whereby said plates are caused frictionally to resist movement of said followers, said last named means including a toggle mechanism operable when either follower is moved towards the other to force said plates into frictional engagement with one another, and means to release said plates from frictional engagement with one another when compression strains on the gear are removed.

6. A draft gear including a pair of followers, means whereby one of said followers is moved towards the other when the gear is subjected to compressive strains, two sets of intercalated friction plates, means whereby said plates are caused 'frictionally to resist movement of said followers, said last named means including atoggle mechanism between said plates and one of saidfollowers operable when either follower is moved towards the other to force said plates into frictional engagement with one anotheiyand means to release said plates from frictional engagement withjone another when compression strains on the gear are released.

7. A draft gear including apair of followers, means whereby one of said followers is moved towards the other when the gear is subjected to compressive strains, two sets of intercalating friction plates, means whereby said plates are caused frictionally to resist movement of said followers, said last named means including a toggle mechanism between said plates and one of said followers and an application spring between said togglemechanism and the other of said followers through which movements of said followers are transmitted to said toggle mechanism to cause thelatter to force said plates into frictional engagement with one another, and means to release said plates from frictional engagement with one another when compressive strains on the gear are removed.

8. A draft gear including an inner fo-llower, an outer follower, stop means limiting inward movement of the inner follower and outward movement of the outer ,follower, a yoke" surrounding said followers, a coupler stem connected with said yoke for limiting longitudinal movement with respect thereto, the inner end of said coupler stem being in abuttin relation to said outer follower, two sets 0 intercalated friction plates one set of which is arranged to be moved outwardly by said inner follower and the other set of which is arranged to be moved inwardly by said outer follower, a

toggle mechanism between said plates and one of said followers for forcing said plates into frictional engagement with one another, and an application spring between said toggle mechanism and the other of said followers through which bufiing and pulling forces imposed on the gear are transmitted to'said toggle mechanism.

9. In a draft gear, in combination, a pair of opposed chamberedfollowers, cooperating friction elements housed within said followers, friction shoes in each follower for engaging said elements, toggle members in each follower, spring means engaging said toggle members for creating alateral pressure on said shoes and elements upon the compression of said gear, and resilient means for resisting the inward movement of said shoes during compression of the gear.

JAMES R. CARDWELL. 

